Kolodvor

If you are using jQuery see this post.

To set focus on first text field with Prototype I prefer something like this

  var firstField = $$('input:text:visible').first();
  if (firstField)
    firstField.focus();

but you can also try with Form.focusFirstElement or Form.findFirstElement

3RAWXQXCQDMZ

f you are using Prototype see this post.

Setting focus on the first text field with jQuery is as simple as

  $("input:text:first").focus();
  $("input:text:visible:first").focus();

Find more at http://docs.jquery.com/Selectors

Update: If you are on Rails use auto_focusable_forms, dependency free plugin that will focus first input for you.